Find the maximum value

hum, very interesting
ok, so we have 5x+4y
we want x and y to be as big as possible
that means we want to pick the most positive x value and most positive y value
ok, by our bounds, te most positive x value is -2
the most positive y value is 6
so the max value iswhen x=- and y=6
that is C=5(-2)+4(6)
C=-10+24
C=14
the max value is 14